Although I could not find any actual, published guidelines, I queried a few of my colleagues and we were all in agreement. You should avoid coloring or perming hair during chemotherapy or while it is initially growing back after therapy. The chemicals used in these and other processes, such as highlighting and hair straightening, can damage hair and can cause it to fall out.

In addition, as the hair grows back after therapy, it is often more fine- almost like a baby's hair- and thus probably will not handle the stress too well. Avoid doing anything to your hair that will cause undue stress. Once your hair grows back to its normal health and fullness (not necessarily length), then make that hair appointment! One of my colleagues did say that for someone who really wants to color it, try using a color wash instead of a hair dye, as this is a bit less damaging.